1. Field of the Invention
The present invention relates to a lighting apparatus for emitting light towards subjects to be photographed by silver-halide cameras, digital cameras, cellular phones, and so on with photographing functions.
2. Description of the Related Art
Recently, a smaller amount of light than before is required for illuminating objects with a lighting apparatus, because of improvements of sensitivity of silver salt films, color films, and charge coupled devices. Therefore, even though the amount of light output by light emitting diodes (LEDs) is smaller than that output by conventional xenon tubes, usage of LEDs as lighting apparatus for photographing is proposed for improved lighting efficiency, reduced power consumption, and increased life.
However, because a single LED can not emit enough light for photographing, an apparatus including a plurality of LEDs as light sources, is proposed.
In the case where a plurality of LEDs, each having narrow illuminating angle is used for a lighting apparatus, the LEDs are arranged to emit light in different directions for uniformly illuminating the entire photographing area of the camera. Therefore, the lighting apparatus has a complex structure. In addition to this, problems with the lighting apparatus, or with handling of the apparatus, can occur because of the concentrated heat produced due to emitting light from a plurality of LEDs arranged close to each other.
Further, it is difficult to control the light emitting direction of LEDs, because a radiating surface of an LED body is generally covered by a lucent resin layer functioning as a protector of the LED body and lens.